It is generally considered desirable to reduce the level of noise within passenger compartments of vehicles. External noises, such as road noise, engine noise, vibrations, etc., as well as noises emanating from within passenger compartments, may be attenuated through the use of various acoustical materials. Sound attenuating materials for vehicles, such as automobiles, are conventionally used in the dashboard, in conjunction with carpeting for floor panels, in the wheel wells, in the trunk compartment, under the hood, as part of the headliner, A-pillars, etc.
Floor coverings, dash insulators, fender well covers, interior trim components, and the like that are designed to attenuate noise may be formed from a laminate having a thermoplastic mass layer and a decoupler fiber layer attached to the mass layer. A mass layer is conventionally a highly filled thermoplastic material (e.g., ethylene vinyl acetate (EVA) with 80% calcium carbonate, etc.). Other materials may include polyethylene (PE), polyvinylchloride (PVC), etc.). A fiber layer may be a batting of one or more thermoplastic fibers.
Floor coverings, dash insulators, fender well covers, interior trim components, and the like, are conventionally molded into a three dimensional configuration to conform with the contours of a vehicle component to which they are to be attached. A laminate is conventionally pre-heated to a specific temperature prior to molding via forced heated air. Although the fiber layer of the laminate can be heated fairly quickly via the use of force heated air, the mass layer may take a very long time to reach the temperature necessary for molding. This delay may add to manufacturing time, and, thus, may increase costs. As such, vehicle manufacturers are continuously looking for ways to reduce the time and costs associated with manufacturing fiber/mass acoustical parts for vehicles.